Kant seems to believe that we can't help but think the idea of a thing in itself, since the idea is analytically connected to the idea of intuition, also perception, and its content, appearance (= the thing as presented to me). 

But while we can cognize appearances, i.e. take them as genuine objects of the concepts we deploy (in synthetic judgments), no such object is available when we think the idea of a thing in itself. For Kant, of course, the constraining factor is presentability in space and time. For Kant all cognition of particulars are, or are rooted in, their spatiotemporal presentation. All cognition is ultimately grounded in the empirical. 

To think of the thing as it is in itself presents no contradiction in thought, but can never be more than an analytical judgment (involving concepts only) since nothing is "given" (no "third thing") to connect it to perception. The thought is "without sense" so far as the possibility of presenting an object. He describes it as a "limiting concept", exhibiting the limits of possible cognition.

On this reading, if defensible, the idea of the ding an sich would have no ontological import.

Noumena appear to exist even if we cannot enumerate their specific properties. That is to say even objects of our imagination are real (sometimes more real than "genuine" real). We can name or iconize things regardless of their existence in the world out there (reality proper). Then we treat such icons as they were (real) things in themselves. Obviously simplistic ontology suffices: icon #1 (or word #1) is this object I point towards (as Kant would probably accept).

Incidentally it seems as if our reality should be as legitimate THING as a "genuine" reality out there. (Just a thought).

A. K. Konopka,

Certainly you are right regarding objects of imagination. And Kant, I think, agrees. However, for Kant the imagination is a capacity literally for imaging (in a broad sense that might include such sensory counterparts as force and aroma). But here the constraining factor of spatiotemporal presentation still applies. So for Kant an object of imagination is still presented as a spatiotemporal object, even though the entire presentation may be merely imagined. So for Kant, a merely imaged object is not noumenal, since it is definitive of the idea of the noumenal that it be presented independently of the presentational conditions of spatiotemporality.

Renzo Bianchi,

I would quibble with your final assertion. "If it is real for you, it is real." Surely we have solid grounds to distinguish between the merely subjective view of things and what is objectively the case. We believe vast periods of human history have gone by during which everyone was simply wrong about the facts. It's in the nature of science that we may discover more "universal errors" in the future. We seem, by our nature, to have the distinction between objective facts and our beliefs about them. And it is in their nature, these facts and beliefs, that they sometimes do not "fit." Kant is, as others are, keen to sustain a robust account of objectivity.

A lot depends on your goal. If you seek to understand the essential reality, then 'things', 'objects', 'subjects', and even 'events' have no value. The essential reality is a dynamic flow of energy through various forms and interactions. Physics must deal with these forms and relationships by creating its own descriptive models and language. If your goal is to master the world we people live in then you must realize that the ideas, words and thoughts of objects and events are what we use to model a way of dealing with our everyday existence. Each person's model can be both different and the same as the next in many ways. Models are not wrong or right. They are situationally useful. They can never truly be the reality.

 Frank,

Shouldn't we say that our most recently accepted physical theory, e.g. one invoking the dynamic flow of energy, is also of value only so far as it is (scientifically) useful? And isn't its usefulness tied ultimately to its explanatory value with regard to our experiences? I.e. the use of the theory gives better predictions, and in general better explanations, of observations we have access to. The physical theory must be tied, in the appropriate way, to phenomena and appearances for its legitimacy. I don't see why we'd want to abandon pragmatic macrostructure having presently settled upon a (pragmatically) successful account of the microstructure.

Renzo,

In fact I think there is something quite Kantian in what you say. Kant thinks there are universal features to subjectivity, There are specific general forms of judgment and specific forms of appearance (space and time). These both make experience possible and account for not only its general forms, but the general forms of its possible objects. This may be the crux of transcendental idealism. So these universal features of subjectivity are the philosophical basis for objective claims. He doesn't think objectivity is undermined by that, since these subjective conditions hold, on his view, for any and all subjects of experience.

Are mathematical objects real? Just curious. Are literary characters real? Are models real? (Frank mentioned them). My suggestion: anything that can be named is real.

Ian

Thank you, yes. I was merely formulating a foundation for development, such as what you have astutely added.

I didn't intend to say that models would be independent or that some would be more useful. I do take your point that 'microstructure' models (presumably a reference to physical models) have the potential to influence and verify the accuracy of 'macrostructure' models (useful in everyday human life). 

Are you suggesting that "idea of the thing in itself" represents some aspect of a microstructure model and would then have better explanatory value then "transcendental idealism" in guiding our pragmatic models?

In my mind, the question becomes, how would "idea of the thing in itself" relate to current physical models? I expect that Physics will soon discover how ideas fit into a more fundamental scheme that would substantiate and explain why their current popular models work.

I suppose you can conclude that I see 'transcendental' explanations as dead ends, which while allowing the exhausted among us to arrive at a conclusion, can prevent further deep investigation.

Frank,

Allow me to address you and A.K. Konopka simultaneously. For Kant mathematical objects are not real. Indeed he might consider them the epitome of the kind of ideal objects to which we have access. For example, he would say, we would never encounter a real triangle. Even when drawing one, it represents a construction of an ideal in "pure" space and time. 

When discussing how all concepts that are meaningful derive their meaning from their spatiotemporal, and ultimately their empirical, "significance" or "sense," Kant says,

"One only need take the example of the concepts of mathematics, and first, indeed, in their pure intuitions. Space has three dimensions, between two points there can only be one straight line, etc. Although all these [i.e. such] principles, and the representation of the object with which this science occupies itself, are generated in the mind completely apriori, they would still not signify anything at all if we could not always exhibit their significance in appearances (empirical objects). Hence it is also requisite for one to make an abstract concept sensible, i.e. to display the object that corresponds to it in intuition, since without this the concept would remain (as one says) without sense, i.e. without significance. Mathematics fulfills this requirement by means of the construction of the figure, which is an appearance present to the senses (even though brought about apriori). In the same science the concept of magnitude seeks its standing and sense in number, but seeks this in turn in the fingers, in the beads of an abacus, or in the strokes and points that are placed before the eyes." (A239--40/B299)

Models are simply more elaborate ideal objects. 

The point Kant is making about the concept of the thing in itself is that it does not satisfy this condition. This concept has, in principle, no such spatiotemporal significance or sense, which is tantamount for Kant to having no meaning at all. The concept is "merely analytically" connected to the concept of appearance. (He argues this point in the "Phenomena and Noumena" section of the CPR.)

This concept, like the concepts of the soul, of God, of the cosmos as a whole, does not, Kant argues, satisfy the conditions of meaningfulness. (For Kant these are the paradigms of ideal objects to which we could never have access. His analysis is in the "Transcendental Dialectic" section of the CPR.) Regarding the latter concepts, this is what the "critique" in the Critique of Pure Reason is all about. So far from creating a dead end, he wants to show that "knowledge acquired from reason alone" is a myth. Perception, experience and our reasoning (theories) regarding what we can experience, he argues, is the source of knowledge. Regarding that, we follow the evidence wherever it may lead.

Another way to approach a response to your criticism, Frank, would be to say that on my reading transcendental explanations are epistemological and not ontological. To be sure, to limit possible knowledge to what can possibly be affirmed in experience limits ontology. But the limits are of the sort you are likely to accept. E.g. there can be nothing real "outside of" time. Nature (the physical) is a thoroughgoing causal order. (Now of course we're faced with the prospect of quantum indeterminacy. And who knows? Perhaps the limits are not the ones Kant envisioned. But the basic idea that we are each in an important sense distinct from the objects we experience--and from each other--this very idea implies there are conditions for our being epistemically related to these objects. Kant's fundamental claim is that in so far as any of these conditions reside with us, that's how for we set the limits. But keep in mind that these "limits", or rather their sources, not only limit ontology in the way described, they also are what make all of possible reality potentially available to us. After all, it is our epistemic capacities that give us access to the world.)

Artur,

I happen to be looking back at your comment just now. (My apologies for not responding at the time.) A counterpart feature of Kant's transcendental idealism, counterpart to the idea of the thing in itself I mean, is its idealism. In the west our era is dominated by physicalisms of various kinds. Any brand of physicalism according to which reasons (reasoning) can be reduced to causes (causal processes), as they say, is bound to be profoundly incompatible with Kant's epistemology. The preeminent influence of neuroscience and the treatment of consciousness as a (causal) free-rider means that Kant's relevance to the discussion is diminished. But anyone concerned to explain (the possibility of) experience, rather than explain it away, will be interested in Kant's work. And if the effort to explain away experience eventually wears itself out, as I think it will, then the kind study of the mind that he and others have pursued will become relevant again.